The Interdigital Glands are located on all four feet.
Each gland is a small sparsely-haired sac that opens between the toes.
In this sac you can generally find a yellowish cheesy material.
This accumulation is the result of sloughed cells and glandular secretions.
The material often has a foul, rancid odor.
Some of this scent is undoubtedly left in a deer's track every time it takes a step.

Several years ago at the University of Georgia they identified several compounds associated with this gland.
They were all small molecules called volatile fatty acids.
Interestingly, these molecules have different volatilities.
In other words, the molecules evaporate off at different rates.
This would cause the odor of the track to change over time, which may be how a deer (or a predator) can tell how old the track is and which way the track is headed.

More recently, a graduate student at the University, conducted a more sophisticated analysis of the compounds associated with this gland.
He identified 46 volatile compounds from the interdigital scent. Interestingly, five of these compounds occurred in much greater concentrations in dominant bucks than in subordinate bucks.
What this may mean to deer is not known, but it is interesting to speculate that a scent specific to dominant bucks may be left by pawing at scrape sites.

Food attractants and lures which appeal to the animals hunger and include ingredients in their diet, and indicate to the animal that there is food here.

Curiosity attractants and lures which are scents that appeal to an animals curiosity.

Matrix attractants and lures which have scents and musk from female animals that are in heat that appeal to a specific animals nature.
They tend to make the animal not so suspicious, because they think one of their own kind was in the area.

Gland attractants and lures, usually made from the glands of animals, which also have the effect of making an amimal think that another of his kind is on his turf.
Gland attractants and lures will also plays on the territorial nature of most furbearing animals.
Most furbearing animals establish a home range which they protect from invaders.
The smell of an animal that is not a member of their group will usually cause an investigation.
This also works both ways, because a trespassing animal will also investigate the smell to determine what other animals are in this range and which ones to avoid.

In theory, attractants and lures will provide a smell that an animal will find attractive.
This being the case, some trappers and hunters believe that an attractant or lure will have an overwhelming and mesmerizing effect on the animal, causing it to cover great distances to investigate the area of the scent location.
In practice, lure is most effective when used at sets made very close to the animal's natural line of travel.
An animal is much more likely to investigate a smell that is close by than one that is far off.
Attractants and Lures are not a substitute for reading animal sign or knowing animal habits.

For an animal to be attracted by an attractant or lure, first it must smell the scent of the atrractant or lure.
That seems like a simple statement, but this is one thing that many trappers and hunters fail to consider when making scent dispenser locations.
The smell of the attractant or lure travels on air currents.
If there is a steady air current or a prevailing wind, an animal traveling on the upwind side of a scent dispenser will not smell the attractant or lure.

Attract and lure quantity and scents also need to be adjusted for temperature conditions.
As temperature lowers, attractants and lures give off less smell, and attractant and lure quantity should generally be increased as temperatures go down.

I went out last night with the intention of killing a pig.
I was trying some new Grim Reaper Attractant and Lure from IN HEAT SCENTS.
Well this is the second time I used the scent and the wind never let up.
As it was getting closer to dark I see this buck approaching.
I can see he has some great brow tines and think oh he's a shooter.
I never really try to look at the horns bowhunting as it has in the past caused me to shake and get a little nervous.
Anyway he came in to the Grim Reaper Scent at 30 yards and he is down.